Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Liabilities
Employee accrued compensation expense	$ 4,682	$ 6,929
Other accrued liabilities	12,508	18,683
Accrued interest on debt	1,586	9,718
Total accrued liabilities	$ 18,776	$ 35,330